Postexercise muscle glycogen recovery enhanced with a carbohydrate-protein supplement

Med Sci Sports Exerc. 2006 Jun;38(6):1106-13. doi: 10.1249/01.mss.0000222826.49358.f3.


Purpose: This study assessed whether liquid carbohydrate-protein (C+P) supplements, ingested early during recovery, enhance muscle glycogen resynthesis versus isoenergetic liquid carbohydrate (CHO) supplements, given early or an isoenergetic solid meal given later during recovery (PLB).

Methods: Two hours after breakfast (7.0; 0.3 P, 1.2 C, 0.1 F), six male cyclists performed a 60-min time trial (AMex). Pre- and postexercise, vastus lateralis glycogen concentrations were determined using nMRS. Immediately, 1 h, and 2 h postexercise, participants ingested C+P (4.8; 0.8 C, 0.4 P), CHO (4.8; 1.2 C), or PLB (no energy). Four hours postexercise, a solid meal was ingested. At that time, C+P and CHO received a meal identical to breakfast, whereas PLB received 21 (1 P, 3.6 C, 0.3 F); energy intake during 6 h of recovery was identical among treatments. After 6 h of recovery, measurement and cycling protocols (PMex) were repeated.

Results: Absolute muscle glycogen utilization was 18% greater (P <or= 0.05) during AMex (C+P: -42.75+/-5.24 mmol.L; CHO: -37.08+/-7.59 mmol.L; PLB: -53.78+/-11.59 mmol.L; P=0.302) relative to PMex (C+P: -38.40+/-4.37 mmol.L; CHO: -31.16+/-3.78 mmol.L; PLB: -40.33+/-1.47 mmol.L; P=0.292), but there were no differences between groups. During 6 h of recovery, muscle glycogen resynthesis was greater in C+P (+ 28.62+/-2.10 mmol.L) versus CHO (+ 22.20+/-1.19 mmol.L, P <or= 0.05) or PLB (+18.50+/-7.67 mmol.L, P <or= 0.05). Cycling performance was similiar (P=0.282) among treatments during both AMex (C+P: 37.61+/-0.63 km; CHO: 37.03+/-0.60 km; PLB: 37.24+/-0.34 km) and PMex (C+P: 36.31+/-0.83 km; CHO: 36.38+/-0.80 km; PLB: 35.34+/-0.45 km).

Conclusions: C+P supplements, given early after exercise, enhance glycogen resynthesis relative to CHO and PLB. However, this does not influence performance in this type of exercise bout.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Adult
  • Bicycling / physiology*
  • Body Weight / physiology
  • Dietary Carbohydrates / administration & dosage*
  • Dietary Proteins / administration & dosage*
  • Dietary Supplements*
  • Energy Intake
  • Follow-Up Studies
  • Glycogen / analysis
  • Glycogen / biosynthesis*
  • Heart Rate / physiology
  • Humans
  • Magnetic Resonance Spectroscopy
  • Male
  • Muscle, Skeletal / metabolism*
  • Physical Endurance / physiology
  • Placebos
  • Recovery of Function / physiology*


  • Dietary Carbohydrates
  • Dietary Proteins
  • Placebos
  • Glycogen